In recent years, it is required that mobile devices such as mobile telephones display the images with high definition. Accordingly, mobile devices which can display high definition images have been rapidly widespread. However, if viewing the image displayed on a screen of such a mobile device, the user viewing the screen may visually recognize so-called coloring (hereinafter, referred to as merely ‘coloring’) on the screen. Such coloring is conspicuous when the mobile device is used outdoors. Since the coloring is obstacle when the user views the image displayed on the screen, it is required to eliminate or reduce the coloring.